The present invention is a method to determine a model-of-composition for petroleum and petroleum related products. In particular the petroleum is a vacuum resid (VR) or vacuum gas oil (VGO) or petroleum with a similar boiling point range.
A vacuum gas oil is a crude oil fraction that boils between about 343° C. to 537° C. A vacuum residuum is a residuum obtained by vacuum distillation of a crude oil and boils above a temperature about 537° C.
Petroleum samples are complicated hydrocarbon mixtures containing paraffins, cyclic paraffins, multiring aromatics, and various heteroatomic hydrocarbons (most commonly O, S, and N). Virgin petroleum crude oils contain molecules of a wide boiling point range from highly volatile C4 hydrocarbons to nonvolatile asphaltenes. Analysis of petroleum composition of various boiling ranges is necessary for inputs to many subsequent processes.